Control for electrical devices



Patented D... 4, 1934 UNITED STATES PATENT OFFICE Claims.

My invention is primarily concerned with lighting systems of a type involving two selectively controllable light-sources, s'uch as the two filaments usually provided in the lamp bulb of an automobile head-lamp. It is the object of my invention to provide in association with two such filaments a control means automatically operable, when one filament burns out while connected to the current-source, to connect the other filament to the battery.

In carrying out my invention, I provide an electromagnetic switch for completing a bridge-circuit from one filament-circuit to the other should an interruption occur in the circuit of the filament which is connected to the source of current.

The accompanying drawing illustrates diagrammatically several embodiments of my invention: Fig. 1 is a somewhat diagrammatic showing of the head-lamp bulbs of a pair of automo- 20 bile head-lamps connected through my control system and selective switch to a source of current; Fig. 2 illustrates another modification'of my invention; Fig. 3 is an illustration of a further modification; Fig. 4 illustrates an arrangement in which my invention is employed in conjunction with the tail-light and stop-light of an automobile; and Fig. 5 is a diagrammatic view illustrating a further modification.

The head-lamp bulbs illustrated in the draw- Ef) ing are of the type commonly employed in present-day automobiles. Each of such bulbs has a lower filament 11 to provide a normal or driving lightbeam, and an upper filament 12, to provide a depressed or non-glaring beam. In such lampbulbs, one end of each filament is grounded, as by being connected to a metal sleeve 13 surrounding the base of the bulb. The ungrounded end of the filament 11 is connected to a contact 11' and the ungrounded end of the filament 12 is connected to a contact 12, both such contacts being shown as disposed at the end of the bulbbase. By these contacts, the filaments are connected to the wiring through which current may be selectively supplied to them.

When the lamp-bulb is in place in its socket (not shown) the contact 11' is connected to a wire 15 which leads to one end of a relay winding 16. The other end of the relay winding 16 is connected through a wire 17 to one of two stationary contacts 18 of the control switch. The contact 12 of each lamp-bulb is connected through a wire 20 with one end of a second relay winding 21, the other end of which is connected through a wire 22 to one of two fixed contacts 23 of the control switch. The movable switch member 24 of the control switch is connected through a battery or other current-source 25 to ground, and is adapted to be moved from the inoperative position shown either into engagement with both contacts 18 or into engagement with both contacts 23.

Conveniently, the two relay windings 16 and 21 are associated with a common core 2'7 in such a Tway that the core will be energized when current flows through either winding. Movably mounted near one end of the core in position to be attracted thereto when the relay is energized is an armature 28 carrying two insulated bridge connectors 29 and 30. Co-operating with the bridge connector 29 are two stationary contacts 31 and 32. A similar pair of stationary contacts 33 and 34 are arranged for co-operation with the bridge connector 30.

As shown in the drawing the contact 31 is connected through a wire 35 with the wire 22, joining such wire at the point A. The contact 32 is connected through a connection 36 to the wire 15, joining such wire at the poirit B. In a similar manner, the contact 33 is connected through a wire 37 to the wire 17 at the point A, while the contact 34 is connected through a wire 38 to a point B on the wire 20.

In the drawing, the device is illustrated in the .condition obtaining when neither lamp-bulb filament is connected to the battery 25. In this 5 condition, the armature 28 is held retracted from the core 27, as by means of a spring 40, the two contacts 31 and 32 being engaged by and interconnected by the connector 29, and the two contacts 33 and 34 being engaged by and connected together through the connector 30. The switch 24 occupies a position where it is out of engagement with both pairs of contacts 18 and 23, and no current is therefore supplied to any of the lamp filaments 11 and 12.

It will be noted that in the condition of the apparatus as just described the ungrounded ends of the filaments 11 and 12 are both connected to the point A in the wire 22. For the filament 11 this connection extends from the contact 11 through the wire 15 to B, and thence through the wire 36, contacts 32 and 31, and wire '35 to the point A. For the filament 12, this connection extends from the contact 12' through the-wire 20, relay winding 21, and wire 22 to the point A. 5 Similarly, the point A is also connected to the ungrounded end of each filament, suchconnec: tion, for the filament 11, leading through the wire 1'7, relay winding 16, and wire 15 to the contact 11'. For the filament 12, this connection leads from the point A through the wire 37, contacts 33 and 34, wire 38, and wire 20 to the contact 12'.

It is therefore apparent that if either of the points A or A' is connected to the battery 25 both filaments 11 and 12 will be connected to the battery. In either case,'however, the connection of one filament to the battery is immediately broken. Thus, if the switch member 24 is placed upon the contact 18 to connect the point A to the battery 25, the resultant energization of the relay winding 16 will cause the armature 28 to be drawn toward the core 27 to break the connection between the contacts 33 and 34, thus interrupting the circuit from the point A to the filament 12 by way of the wires 37 and 38. As a result, while movement of the switch member 23 into engagement with the contact 18 connects both filaments 11 and 12 to the battery, the connection of the filaments 12 to the battery is immediately interrupted, so that only the filament 11 is supplied with current.

A similar action follows movement of the switch member 24 into engagement with the contact 23, such movement serving to connect the point A to the ungrounded pole of the battery. Since the point A, as has been set forth above, is connected to the ungrounded ends of both filaments, both filaments are thereby connected to the battery. One circuit connecting the filament 11 to the battery, however, leads through the contacts 31 and 32, the connection between which is interrupted by movement of the armature following the energization of the relay winding 21 in response to the flow of current in the other circuit. As a result, the connection of the filament 11 to the battery through the switch contact 23 is only instantaneous; and following the interruption of such connection, only the filament 12 burns to provide the desired depressed headlight beam.

In the drawing I have illustrated two headlamps each provided with a double-filament lampbulb. With each head-lamp there is associated one of the electro-magnetic switches or relays such as has been described above, the two relays being identical and being associated with identical circuits.

Let it be assumed that with the movable switch member 24 in engagement with the contacts 18 to illuminate the filaments 11 of both head-lamp bulbs one of such filaments burns out. When this occurs, the fiow of current through the relay winding 16 associated with such filament is interrupted and the relay is de-energized permitting the armature 28 to move to retracted p sition under the influence of the spring 40. When this occurs, the connector 30 serves to interconnect the two contacts 33 and 34, thus completing a circuit from point A to the point B and thence through the filament 12, with a result that the filament 12 becomes illuminated.

In a similar manner, the filament 11 of either head lamp will be connected to the battery should the filament 12 of such headlamp burn out when the movable switch member 24 is in engagement with the fixed contact 23; for when the filament .12 burns out, current flow through the relay winding ceases, and the armature moves to retracted position to complete a circuit from the point A to the point B and thence through the filament 11.

It may be noted that in the last case the retraction of the relay armature which follows burning out of the filament 12 not only provides a connection between the points A and B by way of the contacts 31 and 3 2 but also provides a 0 1- nection between the points A and B by way of the contacts 33 and 34. As a result of this, the point A becomes connected to the point B not only through the contacts 31 and 32 but also through the wire 22, relay winding 21, wire 20 to the point B, wire 38, contacts 33 and 34, wire 37 to the point A, wire 1'7, and relay winding 16. The last mentioned circuit, by reason of the presence in it of both relay windings 16 and 21, has materially higher resistance than the direct p provided through the contacts 31 and 32, with the result that only a very small proportion of the total current supplied to the filament flows through the relay windings, and the springs 40 may be of sufiicient strength to prevent movement of the armature under the effect of such a weak current. If desired, the two windings 16 and 21 on each core 27 might be opposed windings, so that the effect of the current in one winding would counteract the effect of that in the other winding.

In a similar manner current fiows through both relay windings with the switch member 24 on the contact 18 and the filament 11 burnt out. The major portion of the current, however, in such case, passes over the direct path from the point A through the wire 37, contacts 33 and 34, and wire 38 to the filament '12, and the smaller current flowing through both relay windings is insufficient to energize the relay.

While I have illustratedand described my invention as used in association with each of two automobile head-lamps, it may be used in association with any two light-sources or other current-consuming devices which are generally selectively controlled but either of which may be used as an emergency substitute for the other.

In Fig. 2 I have illustrated a device which, while capable of securing the same results as the device illustrated in Fig. 1, is of somewhat simpler construction. As in the construction illustrated in Fig. 1, the arrangement contemplated by Fig. 2 embodies the two-filament lampbulb, the filaments 11 and 12 of which are located respectively in two main circuits in either of which the battery 25 may be connected by the switch 24. In the main circuit including the filament 11 there is a relay winding 16, and in the main circuit including the filament 12 there is a second relay winding 21'. The windings 16' and 21' are opposed windings, and are shown as mounted on a common core 27. Associated withthe core 27 is an armature 45 which serves as the movable contact of a magnetically operated switch having a fixed contact 46 with which the armature 45 is normally held in engagement by a spring 40.

The magnetic switch comprised by the movable and stationary contacts 45 and 46 is connected in a bridge circuit which leads from one main circuit at a' point between the control switch 24 and the relay winding in such main circuit to a point in the other main circuit between its relay winding and filament. As shown in the drawing, the auxiliary switch is connected on one side to the wire 22 and on the other side to the wire 15 to control the electrical connection between such wires.

The device is illustrated, in Fig. 2 with the parts in the position they occupy when neither of the filaments 11 and 12 is supplied with current. If it is desired to illuminate the filament 11 to produce an elevated light-beam, the switch member 24 is moved into engagement with the contact 18 to complete a circuit from the ungrounded pole of the battery 25 through the re:- lay winding 16 to the point D, at which point the circuit branches, one branch leading through the filament 11 to ground and the other branch leading through the auxiliary switch to the point C in the wire 22 and thence through the relay winding 21' and filament 12 to ground. Because of the opposed relation between the windings 16 and 21, the current flowing in the latter has the efiect of opposing that of the current in the winding 16'. The latter winding, however, carries the full current while the former, being short-circuited by the filamentll, carries only a portion of the current. As a result, the effect of the current in the winding 16 is greater than that of the current in the winding 21', the core 27 is magnetized, and the armature 45 is moved out of engagement with the contact 46 to interrupt the bridge circuit between the points C and D, whereupon current flow through the winding 21' and filament 12 ceases.

If a depressed beam is desired from the lamp bulb 10, the switch member 24 is moved into engagement with the contact 23 thus completing a circuit from the ungrounded pole of the battery to the point C. At the point C, the current branches, part of it flowing through the winding 21' and filament 12 to ground, and the remainder flowing through the bridge circuit and thence to the filament 11 to ground. The bridge circuit from the point C to the point D is immediately interrupted, however, as the result of current-flow in the winding 21, and because of this, the connection of the filament 11 to the battery is immediately interrupted.

If, with the switch member 24 on the contact 18 to complete a circuit through the filament 11 as above outlined, the filament 11 should burn out, current-flow through the relay winding 16 would be interrupted thus de-energizing the relay. As a result, the spring 40 would move the movable contact 45 of the auxiliary switch into engagement with the flxed contact 46 to complete the bridge circuit between the points C and D. The closing of the auxiliary switch completes a circuit leading from the ungrounded pole of the battery through the main switch 24, wire 17, and relay winding 16' to the point D and thence through the bridge circuit, relay winding 21', and filament 12 to ground. Under such circumstances, full current flows through both.

relay windings, and because of the opposed'character of such windings the relay remains deenergized and the auxiliary switch remains closed. I

When the filament l2 burns out while the switch member is in engagement with the contact 23,the interruption of current through the relay winding 21' de-energizes the relay and permits engagement of the contacts 45 and 46 of the auxiliary switch. Closing of this switch completes the bridge circuit between the points C and D, and current in the circuit therefore flows from the ungrounded pole of the battery through the switch to the point C and thence through the bridge circuit and filament 11 to ground. It will be apparent; that under such circumstances there is no current fiow in either relay winding, and the relay therefore remains de-energized and the auxiliary switch closed.

In the arrangement illustrated in Fig. 2, Lhave shown each of the main circuits as provided with a fuse 50 between the relay winding and the lamp-filament. Each of these fuses has its normal function of interrupting the circuit upon the occurrence of an over-load or short-circuit. Obviously, since each fuse 50 is in series with its associated filament, the burning out of the fuse will have the same effect as the burning out of the associated filament. In other words, should either of the fuses 50 be burnt out, the resultant interruption in current would close the bridge circuit between the points C and D with the results previously noted.

In Fig. 3 I have illustrated a system in which the burning of a pilot light 55 will indicate the existence of the abnormal circuit conditions which are caused by the interruption of one of the main circuits. In this arrangement there is associated with each of the control relays a pilotlight switch 56 adapted to be closed whenever the associated auxiliary switch contacts 45 and 46 are in engagement with each other. As indicated, the two pilot-light switches 56 are connected in parallel with each other between one side of the pilot lamp 55 and ground. The other side of the pilot lamp is connected to contact points 57 disposed in position to be engaged by the switch member 24 when it is in engagement with" either of the pairs of switch contacts 18 l and 23. The main circuit and the bridge circuit are the same as those shown in Fig. 2. In the operation of the device illustrated in Fig. 3, each of the switches 56 operates jointly with the associated auxiliary switch comprised by the con- 1 tacts 45 and 46. That is, the parts are so arranged that the switch 56 is closedwhenever the associated relay is tie-energized and the contacts 45 and 46 thereof are in engagement with each other. The closed position of the switch 1 56, however, does not complete a circuit through the pilot lamp unless one or the other of the contacts 57 is engaged by the switch member 24. If the switch member 24 is moved into engagement with either of the pairs of contacts 18 and 23, and if all the filaments and fuses are intact, the resultant energization of the relays will open both switches 56, and the pilot lamp will not burn. Should any of the main circuits be interrupted otherwise than by opening of the switch 1 24, the resultant de-energization of the auxiliary relay will cause closing of the associated switch 56, thus completing the pilot-lamp circuit. The pilot-lamp can be located within the range of vision of the operator, who is thereby enabled to note that abnormal circuit conditions obtain.

In Fig. 4 I have shown my invention as embodied in a combination including the tail lamp 60 and stop lamp 61 of an automobile. One end of the filament of the tail lamp 60 is grounded, 1 and the other end is connected through the fuse 50, relay winding 21', and switch 62 to the ungrounded pole of the battery 25. In a similar way, one end of the filament of the stop lamp 61 is grounded, and the other end is connected 1 through a fuse 50, relay windingil6, and switch 63 to the ungrounded pole of the battery 25. The switch 63, as is customary, is arranged to be operated by, the brake pedal to complete the circuit through the tail lamp when the brakes 1 of the automobile are applied. The arrangement embodies the bridge circuit--between the points C and D, such bridge circuit including the auxiliary switch formed by the contacts 45 and 46, as in Figs. 2 and 3. i- The pilot lamp 55 is connected between the wire 15 and ground. With this arrangement, the pilot lamp 55 will be lighted whenever the switch 63 is closed or whenever, with the switch 62 closed, the circuit of the tail lamp 60 is other- 1 wise interrupted; for if the tail-lamp circuit is interrupted otherwise than by opening of the switch 62, the relay winding 21' will be deenergized, the armature 45 will be moved into engagement with the contact 46 by the spring 40, and current will fiow from the ungrounded pole of the battery, through the switch 62, and through the bridge circuit from the point C to the point D, at which latter point it will divide,,

part flowing through the stop lamp 61 and part through the pilot lamp 55.

In Fig. 5 I have illustrated an arrangement which makes unnecessary the use of double contacts, such as contacts 18 and 23, in the manually controlled switch. In this arrangement, the switch member 24 is formed as the armature of an electro-magnet 65 and is movable between two controlling positions in one of which it engages the two contacts 18 and in the other of which it engages the two contacts '23, these two pairs of contacts being connected with the headlamp filaments through the control mechanism illustrated either in Figs. 1 or 2. As shown in the drawing, the armature 24 is biased toward engagement with the contacts 18 and is adapted to be moved out of engagement with such contacts 18 and into engagement with the contacts 23 when the electro-magnet 65 is energized. The manually controlled switch comprises a movable member 24' connected to the ungrounded pole of the battery and two stationary contacts 18 and 23 arranged to be selectively engaged by the member 24'. The armature 24 is directly connected to the contact 18' and is connected to the contact 23' through the winding of the electromagnet 65.

The reasons for arranging the contacts 18 and 23 in pairs, as contemplated in Figs. 1, 2, and 3, is to prevent the closing of the auxiliary switch associated with one head-lamp from causing both filaments of the other head-lamp to burn. This result is accomplished in the arrangement illustrated in Fig. 5 without the necessity for a manually controlled switch of a particular construction. That is, if the manually operated switch member 24' is moved into engagement with the contact 18', the armature 24 remains in engagement with the two contacts 18, and the two wires 17 are connected to the ungrounded pole of the battery 25. At the same time, the two wires 22 are electrically discontinuous. If the switch member 34 is moved into engagement with the contact 23', the relay 65 is energized and moves the armature 24 out of engagement with the contacts 18 and into engagement with the contacts 23 to connect the two wires 22 to the battery and to interrupt the connection between the two wires 17. This arrangement makes it possible to produce a device which can be installed as a self-contained accessory in association with the automobile head-lamps or other electrical devices which are to be controlled, and to do so without the necessity for a manually operated control switch of peculiar character.

I claim as my invention:

1. In a lighting system for automobiles, one or more head-lamps, an electric lamp-bulb for each of said head-lamps, said lamp-bulb having two filaments to produce headlight beams of different characters, a source of current for said filaments, one end of each of said filaments being connected to one pole of said current-source, a main switch having two stationary contacts and a movable contact, the latter being connected to the other pole of saidcurrent-source and being selectively movable into and out of engagement with said stationary contacts, a main circuit and a bridge circuit respectively electrically interconnecting each of said stationary contacts with said two filaments, a normally closed secondary switch in each bridge circuit, and an electro-magnetic device operated by current in each main circuit for opening the secondary switch in the associated bridge circuit.

2. In a lighting system for automobiles, one or more head-lamps, an electric lamp-bulb for each of said head-lamps, said lamp-bulb having two filaments to produce head-light beams of different characters, a source of current for said filaments, a control switch for selectively connecting said filaments to said current-source, and means operative upon the-interruption of the supply of current to either filament when such filament is connected to said current-source by said switch for connecting the other filament to said current-source. I

3. In combination, two main electrical circuits, a source of current, switch means for selectively connecting said current source in said main circuits, a current-consuming device in each main circuit, a bridge circuit interconnecting said main circuits,.a normally closed auxiliary switch in said bridge circuit, and means operative in response to current fiow in either of said main circuits for opening said auxiliary switch.

4. In combination, two main electrical circuits, at current-consuming device in each main circuit, a source of current, main switch means for connecting said current-source in either main circuit, a normally closed auxiliary switch associated with each circuit, means operable in response to current flowing in either 'main circuit for opening the auxiliary switch associated therewith, and two bridge circuits, each of said bridge circuits leading from a point in one main circuit between said main switch and the associated switch-opening means, through the auxiliary switch associated with such main circuit, and thence to the other main circuit at a point between the current consuming device and switchopening means of such other main circuit.

5. In combination, a relay having a fixed contact, a movable contact biased toward engagement with said fixed contact, and two opposed windings, a current-source, two main circuits each including one of said relays and a currentconsuming device, switch means for selectively connecting said current-source in said main circuits, and a bridge circuit including said relay contacts and interconnecting said main circuits.

CHESTER. S. 'RICKER. 

